I've researched and found that the upfront installation costs and ongoing maintenance of a solar system far exceed any cost savings you might gain from it in residential applications. The ROI looks a little better if you live in the house for 30 years (assuming the cells would last that long), can find a good tax credit (but they're very loopholey, applying to the equipment not the installation, for example) and if you can sell your excess production back to your electric provider (which most electric cos. are incapable or unwilling to do).

So, install solar panels because they're cool, or they make you look eco-friendly, but don't perpetuate the myth that there are any real cost savings. The technology is too expensive and inefficient at this time.